The present invention relates to a novel mechanism for the disengagement and retrieval of a strip record representing a measurement of an environmental condition.
Strip chart recorders have been used extensively in cargo containers, intended to transport items over land, sea, or through the air, to record environmental conditions such as temperature, pressure, humidity, and the like. Continuous or strip chart recorders in the past have been quite expensive and have been difficult to load and unload. The latter disadvantage often causes damage to portions of the strip chart recorder such as the stylus or gear mechanism.
U.S. Pat. Nos. 4,222,061 and 4,044,362 show portable strip chart recorders which require opening of the housing of the instrument to load and unload the recording strip which is formed on a cartridge. A slip clutch is required to disengage the gear mechanism of the cartridge.
U.S. Pat. No. 4,007,637 describes a disposable-type temperature recorder which employs a stylus and a clock drive. The tape having the recorded temperatures is removed by unwinding the same from the take-up spool and the remainder of the recorder is discarded.
A strip chart recorder which enjoys the economy and convenience of a disposable-type recorder yet is reusable would be a great advance in the instrument field.